​Located at Partridge Green West Sussex, near Brighton UK Audio Note comprises a sprawling collection of three adjacent, connected industrial units covering warehousing, manufacturing, research and development with a turnover in the low millions Sterling. The organisation has grown like topsy over recent years and is continuing to expand despite its core technologies being primarily based on historic, valve-tubed electronics with top class audio transformers of their own manufacture.

​While their heart is undoubtedly in reproducing analogue audio, where the signal may begin with their own hand made moving coil cartridges, they do not fear digital audio by any means and make fine DACs and CD players including state of the art examples at well over £300,000. £1,000,000 audio systems may be readily assembled with a choice selection of top AN components. Nevertheless several designs are quite competitively priced eg a TT1 turntable with Audio Note moving magnet cartridge, and a ‘Zero’ all valve integrated amplifier. In fact for about £5,000 you can buy an Audio Note audio system, a large pair of speakers, valve amplification and a valve equipped CD player.

Founder Peter Qvortrup has a stock of these amazing Psvane 212 triodes and is determined to build a limited edition SE power amplifier with them. Their original application was driving a high power loudhailer on an aircraft carrier to instruct pilots of fighters and helicopters on the flight deck while under power.

And until the end of 2013 there was also a healthy kit operation. While kits have finished, Audio Note also do good business with their custom audiophile parts which are used by enthusiast constructors and some other manufacturers in addition to their own production lines. While the famous Rubycon Black Gate used by Audio Note capacitors have ceased production (beware of fakes which now widely available) Audio Note are working with Rubycon creating new advanced capacitors, and I noted two types of new electrolytic capacitor of same value, size and voltage but one was much heavier, this a very low ESR type with much lower impedance and a higher material density inside.

A new and stylish tri-motor turntable under development and seen in the research division

​My visit was prompted by a particular development in DAC technology, the research unfolding in over the past year. Experiments with a novel discrete ladder DAC, guided by a belief that selected discrete resistors could sound better than the generally silicon nitride resistive elements used within integrated circuits, led to the design and built of an automatic computerised resistor tester to select from thousands the precise values required to make a DAC of the required precision.

​The favoured resistor technology would not allow laser trimming as is sometimes done. A prototype NOS discrete DAC has now been built where the zero crossing and array switching issues are now addressed and where the trimming of the last bit is allocated to a precision multi-turn resistor. It sounded very well indeed with Kegon triode electronics, promising a step beyond the existing Level Five. The latter uses a selected Analogue Devices 18 bit linear DAC. However there is still much work to be done on this new DAC before its eventual release.